If shipping just a few pieces of chips, taping the chips to a piece of cardboard using masking tape will do.
The key is to prevent the chips from banging onto each other during transit that could result into scratching, chipping and other damages.
Then, insert the cardboard into a padded envelope and mail it. Masking tape is ideal than other kinds of tapes as its adhesive does not stay on the poker chip.
For a larger amount of chips, roll a stack in a piece paper and secure with Scotch tape.
Wrap the stack in bubble wrap and ship in a large padded envelope or small box packed with shredded paper.